A kind of secondary biochemical system sludge reflow treatment system
Technical field
The present invention relates to Waste Water Treatment, relate in particular to a kind of system sludge of secondary biochemical efficiently reflow treatment system, substitute conventional second pond, use the mud reflux type of efficient air-floating apparatus as acidication, anoxic unit or aerobic unit.
Background technology
Along with the improvement attention degree increase of national aspect environmental pollution, industrial enterprise sets up perfect wastewater treatment equipment basically, and conventional secondary biochemical treatment has become the main flow of wastewater treatment.The mud-water separation mode that secondary biochemical adopted often adopts the tupe of second pond, comprises vertical-flow or radical sedimentation basin.Second pond is a principal mode of realizing efficient mud-water separation, also is the important window that realizes that mud refluxes, and simultaneously, the nitrifier of continuous enrichment also is the important means that nitrated/denitrification function is realized in the second pond.Though second pond plays important effect in wastewater treatment process, some drawbacks that it exists in the design and use process: the suspended substance emission standard of (1) increasingly stringent, such as concentration of suspension is less than 20mg/L, second pond is difficult to accomplish generally speaking; (2) second pond precipitating sludge concentration is low, and high quantity of reflux need be set, and the water ratio of second pond mud only can be kept the level about 99.5%; (3) the nitrifier culture cycle is long, and often the nitrifier enrichment needs one month, even more times; (4) temperature influence is very big, and thermal convection and mud come-up problem are the important factors that influences the second pond processing efficiency; (5) general requirement second pond surface load is lower than 1m
3/ (m
2H), floor space is high.
For solving the problem that above-mentioned second pond occurs, a kind of reflow method of biochemical sludge is efficiently proposed, substitute conventional second pond.
Chinese invention patent CN200810034681.8 discloses a kind of mud backflow deposition and remodeling method thereof that is transformed into by tube settler; The inclined tube technology is applied in the second pond; Through increasing the mode of desilting area, reduction surface load, help the sedimentation of active sludge, still can not solve the problem of above-mentioned existence; Only be the raising of deposition efficiency, but not a kind of novel mud backflow model is provided in essence.
Chinese invention patent CN200710068352.0 discloses a kind of treating device for sludge self-return aerobic bios; Through the bucket and the slope of tilt are set in the second pond bottom; Can improve the concentration of precipitating sludge like this; Thereby reduce the amount of returned sluge, it also is the renewal of existing second pond.
Summary of the invention
For solving the present situation that present secondary biochemical system sludge backflow depends on second pond; The object of the present invention is to provide a kind of system sludge of secondary biochemical efficiently reflow treatment system; Substitute second pond, the purpose of entire treatment system is following: the floor space of conventional second pond is practiced thrift in (1); (2) reduce energy consumption and the flow that refluxes; (3) tiny mikrobe flco can be caught by the efficient air-floating system; (4) concentration of suspension of reduction water outlet; (5) culture cycle of shortening nitrifier is maintained nitrated/denitrifying running balance.
Goal of the invention of the present invention realizes through following technical scheme.
A kind of secondary biochemical system sludge reflow treatment system; Substitute original second pond by the dissolved air flotation system, it is characterized in that: said dissolved air flotation system comprises air compressor machine, air reducing valve, pressure volume pot, dissolved air release, mud scraper and mud-collecting slot, and mixed solution gets into the dissolved air flotation system in the biochemical system; Pressurized air in the air compressor machine is got in the pressure volume pot by air reducing valve; Cleaning water is partly refluxed in the pressure volume pot, and packing layer is arranged in the pressure volume pot, forms stable dissolved air water; Formed dissolved air water pressure maintains between 0.3 ~ 0.4Mpa, and the air water ratio of dissolved air water is 20% ~ 50%.Dissolved air water discharges stable microbubble through valve and dissolved air release, and the microbubble that utilizes reliever to form fully separates the microbial bacteria micelle with waste water, guarantees out water suspension less than 20mg/L, and air supporting sludge concentration water ratio reaches about 99%.Cleaning water through dissolved air flotation effluxes through perforated pipe or carries out advanced treatment, and the mud scraper of top mud through being located at the system top is in mud-collecting slot, and the mud in the mud-collecting slot is back in hydrolysis, anoxic or the aerobic system through sludge pump.
Said dissolved air release adopts TC series reliever (Shanghai Mino Environment Technology Company), and the reliever flow is 5 ~ 20m
3/ h, reliever surface fluting number is 6 ~ 8.Dissolved air flotation system surfaces load is 4 ~ 12m
3/ (m
2H), be preferably 4 ~ 8 m
3/ (m
2H).
System of the present invention changes the present situation of the main body that present secondary biochemical system refluxes as mud with second pond, provides a kind of based on the novel mud reflux type of dissolved air flotation for the basis, and air-flotation system does not use coagulating agent and flocculation agent, keeps the character of returned sluge.System high efficiency of the present invention, simple to operate, flexibility is strong.
Be applicable to that the biochemical treatment apparatus in the highly effective sludge return-flow system of the present invention comprises activated sludge process, SBR, CASS, A/O system or the like, the biochemical treatment unit of various industrial organic waste waters is all suitable.
Description of drawings
Fig. 1 is the schematic flow sheet of one embodiment of the present invention.
Label declaration among the figure
1-biochemical system, 2-valve, 3-pump, 4-air compressor machine, 5-pressure volume pot
6-air reducing valve, 7-packing layer, 8-dissolved air flotation system, 9-mud scraper
11-the hydrolysis of 10-mud-collecting slot, aerobic or double oxygen system 12-perforated pipe water exhaust system, 13-dissolved air release.
Embodiment
Further specify the process and the effect of the inventive method below in conjunction with accompanying drawing.
Embodiment 1
Mixed solution gets into dissolved air flotation system 8 through valve 2 and pump 3 in the biochemical system 1, if satisfy the situation of floor plan, directly opens valve 2, lets the mikrobe mixed solution directly get into efficient air-floating separation system 8.Pressurized air in the air compressor machine 4 is through valve 2 controls; And, packing layer 7 being arranged in the pressure volume pot 5 by in the air reducing valve 6 entering pressure volume pots 5, part is back in the pressure volume pot 5 through pump 3 and valve 2 in the perforated pipe water exhaust system 12 of cleaning water from dissolved air flotation system 8; Form stable dissolved air water; Dissolved air water pressure maintains between 0.3 ~ 0.4Mpa, and dissolved air water discharges stable microbubble through valve 2 and dissolved air release 13, and fully reacts back the entering in the dissolved air flotation system 8 with mud mixed liquid and carry out mud-water separation; Mud scraper 9 and mud-collecting slot 10 are arranged at the air-flotation separation equipment top, and the surface load of dissolved air flotation system 8 can be accomplished 6 ~ 12m
3/ (m
2H), the surface load well below conventional second pond designs.Thickened sludge in the mud-collecting slot 10 is back to hydrolysis, aerobic or double oxygen system 11 through pump 3 and valve 2; Also can use gas to carry spoil disposal; Directly get into hydrolysis, aerobic or double oxygen system 11, realize that mud refluxes or the structure of nitrated/denilrification system through valve 2.
Embodiment 2
Certain pharmacy waste water designs former use technology and is " equalizing tank+preliminary sedimentation tank+acidication+A/O technology+radical sedimentation basin ", and COD is 500 ~ 600mg/L in water inlet, and ammonia nitrogen concentration is 70 ~ 80mg/L; When suspended substance is 400 ~ 500mg/L, require the water outlet ammonia nitrogen less than 5mg/L, suspended substance is less than 20mg/L; COD is less than 40mg/L, and original design water outlet COD is less than 50mg/L, and ammonia nitrogen is less than 10mg/L; Suspended substance transform radical sedimentation basin as the efficient air-floating separation system less than 40mg/L, goes out water suspension less than 15mg/L at present; COD is less than 35mg/L; Ammonia nitrogen is less than 5mg/L, and return sludge ratio originally was set to 100% and refluxes, and was reduced to the sludge concentration that 20% backflow just can be kept aerobic system earlier.The former sludge concentration that is introduced into sludge thickener is about 99.2%, gets into the sludge thickener moisture percentage in sewage sludge behind the use air-flotation system and maintains between 98 ~ 99%, and volume reduces significantly.
Embodiment 3
Certain wastewater from chemical industry water inlet COD concentration is 800 ~ 1000mg/L, and ammonia nitrogen concentration is 100 ~ 150mg/L, B/C=0.3; Use this highly effective sludge return-flow system at present; The nitrifier culture cycle shortened to for 1 ~ 2 week by conventional 1 ~ 2 month, and the water outlet ammonia nitrogen concentration is less than 10mg/L, and the surface load of air supporting simultaneously is 6 m
3/ (m
2H), practiced thrift floor space.
Embodiment 4
Certain sub-district intermediate water reuse system, water inlet COD is 300 ~ 400mg/L, and ammonia nitrogen is 30 ~ 45mg/L, takes up an area of to require to economize, and the water yield is 2000m
3/ d originally pressed the second pond design, needed to take up an area of 100m
2, to take up an area of hugely, the wastewater treatment that the sub-district lacks area like this is taken up an area of, and the back uses the dissolved air flotation system to reflux as mud and mud-water separation is equipped, and surface load is designed to 8 m
3/ (m
2H), can build jointly, need not consume floor space basically with aerobic system.Simultaneously, mud refluxes and significantly reduces.
Embodiment 5
Certain spices is made waste water; Original second pond mud often floats, and forms " spot " one by one at the radial-flow type sedimentation pool surface, even accelerate the suction mud frequency of suction dredger; Can not reduce the situation of mud come-up, main is that second pond inevitably has the dead angle because of one; The 2nd, the mud biodegradability is good, forms anaerobism in the bottom in very short time and floats; Existing with second pond improvement cost highly effective sludge reflux; Solve the problem while of mud come-up, return sludge ratio is reduced to 10% by 50%, and the concentration basin moisture percentage in sewage sludge is reduced to about 98% by 99.3%; Reduced by 2/3 sludge volume, helped the normal operation of sludge dewatering system.